Compressor valve



l1ll3,536,094

United States Patent Patented Oct. 27, 1970 y 3,536,094

Sheet 1 of 2 F E. M/VLK Jl.' F IG. 2 A y y INVENTOR.

A TTORNEVS COMPRESSOR VALVE BACKGROUND OF THE INVENTION Piston typecompressors commonly utilize freely moving intake and discharge valves,located in the cylinder head or between the cylinder and the cylinderhead of the compressor for controlling the intake and discharge offluids or gases by the compressor. Valves commonly employed in presentcompressors provide unidirectional flow into and out of the compressorcylinders and are known in the art. Conventional valves of this typethat are generally provided have perforated flat circular plates ofalloy sheet steel or a multiple series of concentric flat steel sealingrings biased toward the valve seat by coil springs or spring plates.These valves control fluid or gas flow by the reciprocal movement of theconcentric sealing rings or the circular plates between a closed orsealed position with machined seating surfaces and an open positionwherein the rings are displaced from sealing engagement with thesesurfaces to permit fluid or gas flow through the valve.

The efficiency of piston type compressors is largely dependent upon thecharacteristics of the flow valves through which intake and discharge ofthe fluid or gases take place. In the compressor valves commonly in usetoday. there is an appreciable velocity head loss occasioned by problemsin moving the fluid through the valve at high velocity. The problems arelargely caused by energy losses resulting from violent changes in flowdirection. frictional interference and turbulence by the fluid as itpasses through the compressor valve and around the sealing surfaces.Thesev problems are especially critical in attempting to obtain optimumefficiency and capacity in high speed compressors, operating in therange of 400 to 2000 strokes per minute. The optimum performance of thecompressors, which by their nature have a very short stroke, requiresvalves which not only permit flow of the fluid or gases to and from thecylinder with a minimum of pressure loss and at a high velocity. butwhich will also seat rapidly and positively during the critical pressurereversals which take place at the beginning and end of the intake anddischarge strokes. In such high speed compressors, the valves may besubjected to extremely high pressures and temperatures. At highcompression speeds the reciprocal movement of the rings or platesagainst the seating and stopping surfaces within the valve case isextremely rapid and under high pressure` the rings slamming into theseating and stopping surfaces at high speed and with great force. Suchrapid high velocity movementy and impact causes the valve seatingsurfaces to become pitted and rough, allowing fluid or gas leakageduring the intake stroke. In addition, the noise level associated withsuch valves is very high and disagreeable for workmen who must work inproximity to the equipment.

The present invention remedies these problems by the use of sealingrings or plates of a synthetic resin having novel sealing and engagingsurfaces.

SUMMARY OF THE INVENTION The instant invention provides a novelcompressor valve utilizing concentric sealing rings or circular sealingplates constructed of a suitable synthetic resin. The basicconfiguration of the rings or plates is conventional, having a flatupper surface and a discrete thickness with rounded or straight verticaledges, but having a downwardly convex protruding sealing surface toengage recessed seating surfaces in the valve seat. The recessed seatingsurfaces are angularly disposed to the flat inner surface of the valveseat member and engage the convex sealing surfaces of the sealing ringsor plates to interrupt fluid or gas flow through the compressor valve.The synthetic resin of which the sealing plate or rings are constructedis selected to include the following primary characteristics: generallynonresilient, high-impact and high-temperature resistant, and resistantto corrosive chemical action.

In addition, the valve case comprised of the valve seat and valve guardmembers is of a unitary design` This unitized construction utilizesinterrupted screw threads for easy and time saving disassembling. Thisunitized construction feature eliminates all through bolting for the useof'setscrews which often are difficult to remove after the valve hasbeeninstalled and in use over long periods of' time. Further, after longperiods of use, the tremendous forces and vibration acting on the valveoften cause the bolts or other retaining means holding the valve guardand seat, members'together to fail and allow metallic pieces of suchbolts or setscrews to fall into the valve and into the compressorcylinder which can cause extensive damage. The use of the interruptedscrewthread unitized construction makes the task of maintenance andinstallation easier and simplifies the assembly of the valve after anyfield repair. The valve case has such symmetrical dimensions and is soconstructed that the valve may be used as an intake or discharge valvewithout modification, simply by inverting the valve itself.

Accordingly, it is a primary feature of the present invention toprovidea compressor valve that minimizes the velocity and pressure loss throughthe valve and increases compressor efficiency and capacity.

Another primary feature of the present invention is to provide acompressor valve that may be used either as an intake or.1dischargevalve without modification.

vAnother primary feature of the present invention is to provide acompressor lvalve assembly utilizing sealing rings or plates constructedof a synthetic resin that will not damage the compressor cylinder orcylinder walls in thc event that the sealing rings or plates fail duringoperation.

Another feature of the present invention is to provide recessed seatingsurfaces having a geometrically symmetrical cross section thatself-center geometrically symmetrical crosssectioned sealing surfaces ofa sealing plate or concentric sealing rings or annular projectingsurfaces engaging the seating surfaces.

Itis yet another feature of thc present invention to provide acompressor valve assembly of unitized construction utilizing interruptedscrew threads for easy and simplified assembly' and disassembly.

Itis yet another feature ofthe present invention to provide a compressorvalve assembly utilizing sealing rings or plates ofa synthetic polymericmaterial that dramatically reduces the noise level of the compressorvalves during operation.

"Another feature of the present invention is to provide a compressorvalve wherein the valve ring or plate movement during opening andclosing of the valve may be varied by utilizing synthetic resin rings orplates of different thicknesses.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the manner in which theabove-recited advantages and features of the invention are attained, aswell as others which will become apparent, can be understood in detail,a more particular description of the invention may be had by referenceto specific embodiments thereof which are illustrated in the appendeddrawings, which drawings form a part of this specification. It is to benoted, however, that the appended drawings illustrate only typicalembodiments of the invention and therefore are not to be consideredlimiting of its scope, for the invention may admit to other equallyeffective embodiments.

In the drawings:

FIG. 1 is a perspective view, partly in cross section, of a compressorvalve assembly accordingto the present invention utilizing concentricsealing rings` FIG. 2 is a detailed vertical cross-sectional view of thecompressor valve according to this invention taken along lines 2-2 ofFIG. l.

FIG. 3 is a detailed horizontal cross-sectional view of the compressorvalve assembly shown in FIG. l as taken along lines 3-3 of FIG. 2.

FIG, 4 is a detailed partial vertical cross-sectional view of a portionof the compressor valve assembly shown in FIG. l with the valve shown inits closed condition.

, FIG. 5 is a detailed partalvertical cross-sectional view of a portionof the compressor `assembly shown in FIG. 1 with the valve shown in itsopen position.-

FIG. `6v is a detailed` horizontal cross-sectional view of a compressorvalve assembly according to the present invention utilizing a circularplate having concentric sealing surfaces.

FIG. 7 is a detailed partial vertical cross-sectional view of the valveVseat recessed `seating surfaces and the sealing,k

` member of another' embodiment ofthe compressor valve. t

DESCRIPTION OF THE PREFERREDEMBODIMENTS Referring now to the ldrawingsand first to FIG. l, a perspective view, partially in cross section, ofafcompressor valve 10 i according tothe present invention is showncomprising a valve `guard 11, a valve seat member 16, concentric annularsealing;

' rings 30 and coil springs 28.

Cylindrical valve guard 1l has an internal interrupted screw I t threadsurface 12 aboutits inner periphery of projecting rim 13 that mates withouter interrupted screw thread segments 14 of cylindrical valve seat` 16to hold the inner surfaces of the guard and seat in a desired parallelspaced-apart relationship.

gages the concave valve seating surfaces 32 to close the annul larandsemicircularapertures 34 and 36respectively.

' Coil spring members 28 are disposed within spring retaining apertures26 drilled into the inner vface of valve guard in a predeterminedspaced-apart configuration. Semicircular apertures 22 are disposedbetween ring stopping surfaces 18 and `20 and provide open communicationbetween `the top surface ofthe guard 1l and the interior` of valve 10.An axial rcircular openin`g24 through guard l1 and regularly spacedcircular i `apertures 23`disposed radially about guard ll and adjacentits outer edge also provide communication with `theginterior of valvel0.l

A detailed vertical cross-sectional viewof thecompressor valve shown inFIG. 1 is provided in FIG. 2..Va|ve guard I1 is shown threadablyattached to valve scat member 16 to maintain the inner surface of guard1l in a spaced-apart relation to compressor. Y

Concentric rings 30 are shown with their convex lower surfaces3lsealingly engaging theconcave seating surfaces 32 of seat 16.` Rings30 are biased in their sealed position by coil springs 28 recessed inretaining apertures `26'within the interior face of guard 11. Ringstopping surfaces 18 `and 20'of guard 11 are shown in their spaced-apartrelationship directly above rings 30. With rings 30 in sealing contactwith vsurface 32 of Rings30 have` a lower convex surface 3l` that.tsealingly cn- Referring now to FIG. 3, a horizontal `cross section'ofthe compressor valve l0,shown in FIGS. land 2 is illustrated. An outersection of rim` 13 of guard `ll is shown threadably attached to valveseat `I6 and a semicireularportioit of rings 30 areshown in theirsealing engagement with seat 16."The lower coil of springs 28 is shownengaging rings 30 and urging the rings downward intosealing engagementwiththe seating surl faces 32 of seatmember 16, thereby closingapertures 34 and 36. The sealing rings of the present invention andshown in i FIGS. 1-3 aremade of a synthetic polymeric material which isresistant to high temperatures and the high-impact stresses normallyoccurring in compressor valves of this class. `The use of such materialsappreciably` decreases `the noise, ,level generally associated withautomatic ring ]valves of this type and' providesa more positive "sealas `will be hereinafter described. Further, rings 30 constructed ofsuchmaterials are lighter and require springs 28 of a lighter-springrate than `would be necessary if the rings were of metal. Another factor`in utilizing such syntheticV polymeric materials is the tremen` douslyreduced cost at which the rings may be manufactured over presentlyusedmetal sealing rings. t

Referring now to `FIGS.4 and 5, detailed vertical `partialcross-sectional views of the valve are illustrated and show the rvalvering `seating and liftingaction during' operation. Valve guard 1I isshown in its parallel spaced-'apart relationship to w valve seat 16.Ring 30 is shown disposed in the space between guard Il andseat In FIG.4;.rin`g30fis shown in sealing contact with recessed concave seatingsurfaces 32, while in FIG. 5. ring 30 is shown engaging ring stoppingsurfaces 20 of guard 1l. Spring 28 is shown disposed` within recessedaperture 26 in theinside face of'guard Il. Apertures 22 and 23 are valveseat 16, apertures 22, 23f and 24 are sealed to fluid or gas passage inthe directionindicated by the iarrow A in FIG. 2,

thus closing the valve. Springs28 make contact with the top surface oftheir respective concentricV rings` urging them into sealing engagementwith seating surfaces 32 of valve seat'16.4 When'fluid or gas pressure'is directedthroughapertures v34 i and 36 of seat 16 in a direction asindicated by the arrow B an 3l. Springs 28 resistthis upward forceexerted bythe fluid or gaspressure against theopposite convex ring face31, until the .1 fluid or gas pressure overcomes the springforce andmoves or. "lifts the rings 30 to the open position againststopping'surfaces 18 and20 of guard l1. Rings 30 lift until they makeVcontact with stoppingsurfaces 18`and 20and compress the springs 28within thespring retaining apertures26. The lift" of the valve isdefined as `the distance that rings 30 travel from sealing engagementwith seating surface 32 to the full open position in contactwithfstopping Vsurfaces 18 and 20,"as indicated bythe interval FIG. 2.

shoiwn in guard llfand a portion of aperture. 34 is shown disposedthrough seat 16.` o

Referringnow to FIG. 4, ring `30 is shown having a convex lowersurface31 in sealing engagement withza concave seating surface 32 of seatmember 16. Ring 30 is urged into this sealed position by the action ofcoil spring 28 togprevent fluid or gas passage throughapertures 22and 23indicated by the arrows A y p fWhen fluid or gas flow reverses andfisinthe direction ini, `dicatedby the arrow B.\an upward pressureisapplied against surface 3l of rings 30 throughfaperturcs 34 and 36 (seeF IG. 2), while spring 28 is resisting the upward movement or liftf ofthe rings through the interval indicated at X as hereinbefore l -4defined. In FIG; 5,`ri ng 30 is shown in its lifted position with itsupper surface in contact with ring stopping ,surface 20 and` i havingcompressed spring 28 within its retaining aperture 26. With rings 3 0lifted against ring stoppingi surfaces 20'and I8 (see FIG. 2) ofguardl1,.fluid 'or gas flow 1in the direction indicated by the arrow Bthrough apertures 34 and 36 (see FIG.

`2) of valve seat 16 is allowed to` flow between the'convex ring face 31and the concave seating surface 32.as indicated by the arrows C, therebyallowing the fluid or gas topass upwardly through apertures 22 and 23 inguardllas `indicated by the arrows D. With rings30 in their liftedposition, valve 10 is in its open position andwith rings 30 in theirseated position,

` upward force will be exerted against theconvex ring surface `valve 10is in its closed position.

The concave seating surfaces 32employed inv valve seat member 16 providefora more s'treamlinedfflow of fluid or` gases through thevalveresultingin a smallerpressure drop and increasing compressorefficien'cyand capacity. `An appreciable velocity head` loss through .acompressor valve is generally occasioned by problems in moving the fluidor gases Vthroughthe valve at high velocity, the problems largely being`caused by energy losses resulting from `violent changes in flowdirection, fricitonal interference and turbulence. If the seatingsurface 32 communicating with aperture 134 Alin valve seat 16 had alsquare shoulder, as is commonly usedwin present compressor valvesrthefluid or gas lflow as indicated by arrow B in' FIG. 5 would have to maketwo 90 reversals in direction in moving from aperture 34 to aperture 23of `valve guard 1l in the direction shown by the arrows-B and D These,abrupt changes in the fluid or gases around the sealing ring and itsseat cause frictional interference and turbulence in the flow stream ateach such direction change increasing the energy loss and contributingto the total velocity and pressure transfer loss through the compressorvalve.

As may be seen in FIG. 5, the fluid or gas flow through aperture 34 andbetween convex surface 31 of sealing ring 30 and the recessed concaveseating surface 32 curvilinearly alters the direction of the flow of thefluid as indicated by the arrows C and directs the fluid or gases in acircular upward path around sealing ring 30 and toward apertures 22 and23 of guard 1I. There are no abrupt reversals or changes in direction ofthe fluid or gas flow; thus, frictional interference and turbulence areminimized and energy losses are decreased, resulting in a smallerpressure drop through the compressor valve and correspondinglyincreasing compressor efficiency and capacity.

The use of a geometrically symmetrical cross-sectional sealing surface3l on sealing ring 30 and a geometrically symmetrical cross-sectionedseating surface 32 eliminates the need for ring guides commonly employedto guide the rings 30 vertically during the lifting and downward seatingmovement. Such ring guides trap foreign material which falls on thevalve seating surface causing abrasive wear to the sealing surfaces ofthe conventional disc sealing rings. The convex ring sealing surface 31eliminates the need for such ring guides since the rings 30 will beself-centering when closed, asshown in FIG. 4, and convex ring sealingsurface 31 engages the concave seating surface 32 of valve seat memberI6.

Utilizing concave seating surfaces, as herein disclosed, will furtherreduce -the wear occasioned by the high velocity impact between therings 30 and seat member I6, since the actual area of the engagedseating surfaces of concave cross section will be greater than the areasof thc planar seating surfaces presently utilized in valves of the'sameclass. With the high velocity impacting forces spread over a greatersurface area of the sealing rings 30 and seating surfaces 32, wear onthese surfaces is significantly decreased. Further, as may be seen, thedownward slope of the seating surfaces 32 into apertures 34 and 36produces a self-scavenging action, since foreign material falling on theseating surfaces 23 will be pushed into apertures 34 and 36 by theseating action of rings 30, thereby cleaning seating surfaces 32 andpreventing a buildup of foreign material that may abrade the surfacesand interfere with positive sealing.

It will be noted, however, that many of the advantages and featuresexhibited by the sealing rings 30 having a projecting convex sealingsurface 3l and constructed of a suitable synthetic polymeric materialmay be obtained by utilizing steel or other metal rings having the sameseating surface contiguration. Of course, it will be seen that the useof metal rings will not effect the same decrease in noise level as wouldbe obtained by the use of synthetic polymeric materials.

Although symmetrical cross-sectioned seating andsealing surfaces havebeen found to be particularly advantageous in eliminating fluid or gasflow turbulence and providing a positive sealing means that isself-centering, it may be seen that other surfaces have a geometricallysymmetrical cross section may be advantageously employed. For example,the sealing surfaces of the rings and plates may be of a convexconfiguration for seating with angular planar seating surfaces 32,sloping towards the passage part, as shown in FIG. 7. Of course, othersealing and seating surfaces having protruding curved or planar surfacesor combinations of differing such surfaces may be employed to achievethe features and advantages of the present invention.

Valve lift as indicated at X in FIG. 4 may be easily controlled in thecompressor valve shown in the present invention by varying the thicknessof the sealing rings 30. This would allow the use of a standard sizevalve guard 1l and valve seat 16 to be used in various compressorsoperating over variable ranges of speed and capacity without having tomodify the' design of the guard or seat members to vary the spacebetween their respective internal surfaces, as indicated by the intervalat Y in FIG. 5. Thus, one valve case employing a standard size valveguard l1 and seat 16 may be employed utilizing sealing rings 30 of onethickness for use in one compressor, and the same size valve caseutilizing sealing rings 30 of a second thickness may be used in anothercompressor. The rings would be easily interchangeable between standardsize valve assemblies.

Of course, it may be seen that various coil spring assemblies 28, havingdifferent spring rates to control lifting and closure speed of thesealing rings 30, may be necessary with different thicknesses of rings.Spring cavities 26, of course, are capable of different arrangements asto size and location; they may be oblong or square in cross section. Thesprings 28 may also be changed as to size, their cross section may be ofa square or flat` material. In addition, it should be understood thatalthough the specific embodiment herein illustrated shows the use ofregularly wound helical coil springs, other springs, such as Bellevillesprings, radial disc springs, or spring plates and other spring members,may also be employed.

Referring now to FIG. 6, a horizontal cross-sectional view of the;compressor valve according to this invention is shown wherein a circularsealing disc instead of several discrete rings is employed to performthe sealing function. Valve l0 is comprised of a guard member 11 and abase seat member 16 as hereinbefore described. Seat member 16 hasarcuate and semicircualr openings 34 and 36 for allowing fluid passagethrough the seat member 16. Seating surface 32 has a recessed crosssection identical to that hereinbefore described.

Sealing plate 40 is a thin circular disc having concentric surfacesprojecting from its lower face to form concentric projecting rings,indicated at 44. These projecting ring surfaces 44 have a projectingconvex surface to sealingly engage the recessed cross-sectioned seatingsurfaces 32 of seat I6. Between rings 44 are curved slotted ports 50,separated by a web 48, for allowing fluid flow through the disc. Fluidor gas flow will also be directed around the outer edge of the disc inthe space 52 between the outer edge of the di'sc 5l and the insidecylindrical surface 52 of guard ll. Springs 28 areshown disposed in acircular arrangement to bias plate 40 and its con- Vexv seating surfaces44 toward scat member 16.

Plate 40 may conveniently be constructed of a synthetic polymericmaterial as hereinbefore described for sealing rings 30 and would, ofcourse, enjoy the same advantages and features as hereinbefore detailed.As may be readily seen, a disc plate 40 could be constructed of anysuitable material such as steel.

The operation ofthe valve as seen in FIG. 6, in opening and v closingand the fluid or gas flow through the valve is identical As hereinbeforediscussed in describing the operation of sealing rings 30, the sealingsurfaces of the rings and the seating surfaces of the valve seat memberare not limited to the symmetrical cross section herein described, butsuch sealing and seating surfaces having other geometrically symmetricalor projecting curved or planar cross sections may advantageously. beemployed as hereinbefore described. y Numerous variations andmodifications may obviously be made in the structure herein describedwithout departing from the present invention. Accordingly, it should beclearly understood that the forms of the invention herein described andshown in the FIGS. of the accompanying drawings are illustrative onlyand are not intended to limit the scope of the invention. 4

I'claim: l. A compressor valve, comprising: an annular valve guardmember having a rim circumferentially projecting from the face of saidguard member, the inner surface of said rim having disposed thereoninterrupted screw threads;

an annular valveseating member having arcuate passage` portstherethrough and recessed seating surfaces commuy nicating with saidarcuate passage ports, said vseating member having interruptedscrewthreads disposed about the outer edge offsaid seating member forcooperatively Y mating with said interrupted screw threads of said guardmembenfor removably attaching'said guard and seating members togetherand, spacing said recessedseating sur faces from said guard member;

sealing means of synthetic resin disposed within said space Y betweensaid guard member-and Saidrecessed seating surfaces and adapted formovement therebetween.' said` sealing means having projecting-convexsealing surfaces for engaging said recessed seating surfaces to sealsaid arcuate passage portsfand v- Y 1 means disposed between said guardmemberand said sealing means to urge said sealing means into sealingengagement with said recessed seating surfaces.V

2. The compressor valvedescribed in claim; l. wherein said sealing meanscomprises aty least `one annular sealing ring having azconvex sealingsurface engageable with'said recessed seating surfaces of said arcuatepassage ports. i

.with said seatingsurfaces comprises a4 plurality of springs.

7. The compressor valve described in claim l, wherein said 'recessedseating surfaces communicating@ with said arcuate `passage ports have aconcave configuration..

8. The-compressor valve described in cla'im 1,"wheren 'said recessedseating surfacescommunicating with said arcuate vpassage ports haveanangledplanar` configuration sloping "toward said passage ports- 3. Thecompressor valve as described in claim 2..whc'rein A.

said at least one annular sealing Aring may bc constructed of varyingthicknesses to control the lift of said sealing ring "dur-` ing valveoperation.,

4. Thecompressorvalve described in claim 1,1.wherein saidA sealing meanscomprises an apertured sealing plate one side of p which has at leastone annular convex sealing surface projectt ing ,therefromVsaid convexsealingv surface engageablc with said recessed seating surfaces of saidarcuate passage ports.

5. The compressor valve as described in claim 4` wherein f saidapertured sealing plate may be constructed of varying y thicknesses tocontrol the lift of said sealing plate during valve operation. y

6.\\The compressor valve describedin claim '1. wherein said means forurging said sealing means into sealing engagement prising:

with said-interrupted screw threads of said guard member g for removablyattaching said guardand seating members said guard member; v l aplurality of concentric annular sealing rings of a synthetic together`and spacing said recessed `seating surfaces from resin havingconvexrsealing surfaces for engaging said r recessed seating surfacestoseal said plurality of arcuate passage ports; andV a plurality ofsprings disposed between saidK guard member and each4 of said concentricannular sealing` rings to urge said sealingV rings into sealingengagement with said Y recessed seating surfaces. y

l0; The compressor valve deseribedin claim 9. `wherein said recessedseating surfacescommunicating-with said` arcuate passage ports have aconcave configuration.

11. The compressor valve described in claim 9, wherein'said recessedlseating surfaces communicating with said arcuate passage ports have anangled planar toward said passage ports.

sofl

9.. A valve suitable for'use in a" high' speed compressor, com-y lconfiguration sloping gygo UNlTED STATES PATENT OFFICE CERTIFICATE 0FCORRECTION Patent No. 3,536,0911 hated october 2l, 1970 Invent01`($0Flavious E. Ma'nlev. Jr.

It is certified that error appears in the above-identified patent andthat: said Letters Patent are hereby corrected as shown below:

Col. 8, line ll, insert the following paragraph: 'an annular guardmember having a rim circumferentially projecting from the face of saidguard member, the inner surface of said rim having disposed thereoninterrupted screw threads,

sumen um sEAu-:n

FEE 21W! (SEM.) Annu Edward M. Fletcher, Ir.

WILLIAM E. SGHUYLER, JR. Amunt! 0mm Gomissiom or Patent!

